- 1. Evaluation of the antimicrobial activity of various concentrations of Tulsi (Ocimum sanctum) extract against Streptococcus mutans: an in vitro study.
AIM:
To determine if Tulsi (Ocimum sanctum) extract has an antimicrobial activity against Streptococcus mutans and to determine which concentration of Tulsi (Ocimum sanctum) extract among the 15 concentrations investigated has the maximum antimicrobial activity.
SETTING AND DESIGN:
Experimental design, in vitro study, Lab setting.
MATERIALS AND METHODS:
Ethanolic extract of Tulsi was prepared by the cold extraction method. The extract was then diluted with an inert solvent, dimethyl formamide, to obtain 15 different concentrations (0.5%, 1%, 1.5%, 2%, 2.5%, 3%, 3.5%, 4%, 4.5%, 5%, 6%, 7% 8%, 9%, 10%) of the extract. 0.2% chlorhexidine was used as a positive control and dimethyl formamide was used as a negative control. The extract, along with the controls, was then subjected to microbiological investigation to determine which concentration among the 15 different concentrations of the extract gave a wider inhibition zone against Streptococcus mutans. The zones of inhibition were measured in millimeters using a vernier caliper. Results: At the 4% concentration of Tulsi extract, a zone of inhibition of 22 mm was obtained. This was the widest zone of inhibition observed among all the 15 different concentrations of Tulsi that were investigated.
CONCLUSION:
Tulsi extract demonstrated an antimicrobial property against Streptococcus mutans....(more)
Agarwal P, et al. Indian J Dent Res 2010 Jul-Sep;21(3):357-9.
Related Products: Ocimum Sanctum Extract
- 2. Antioxidant Activities of Hydroalcoholic Extract of Ocimum sanctum Against Cadmium Induced Toxicity in Rats.
The present study was undertaken to analyze the antioxidant (both enzymic and nonenzymic) activities of leaves of Ocimum sanctum hydroalcoholic extract against cadmium induced damage in albino rats. Oral administration of cadmium as CdCl(2) (6.0 mg/kg body weight) led to significant elevation of lipid peroxidation (LPO) levels and significantly decreased Superoxide Dismutase (SOD), Catalase (CAT), Glutathione Peroxidase (GPx), Reduced Glutathione (GSH) and Vitamin C (Ascorbate) levels. Administration of Ocimum sanctum extract (100 mg/kg body weight, po) and (200 mg/kg body weight, po) before and after cadmium intoxication showed a significant decrease in LPO levels and significant increase in SOD, CAT, GPx, GSH and Ascorbate levels. The results suggest that oral administration of Ocimum sanctum extract provides significant protection against cadmium induced toxicity in Wistar albino rats....(more)
Ramesh B, et al. Indian J Clin Biochem 2010 Jul;25(3):307-10.
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- 3. Ocimum sanctum extracts attenuate hydrogen peroxide induced cytotoxic ultrastructural changes in human lens epithelial cells.
Hydrogen peroxide (H2O2) is the major oxidant involved in cataract formation. The present study investigated the effect of an aqueous leaf extract of Tulsi (Ocimum sanctum) against H2O2 induced cytotoxic changes in human lens epithelial cells (HLEC). Donor eyes of the age range 20-40 years were procured within 5-8 h of death. After several washings with gentamicin (50 mL/L) and betadine (10 mL/L), clear transparent lenses (n=6 in each group) were incubated in Dulbecco's modified Eagle's medium (DMEM) alone (normal) or in DMEM containing 100 microm of H2O2 (control) or in DMEM containing both H2O2 (100 microm) and 150 microg/mL of Ocimum sanctum extract (treated) for 30 min at 37 degrees C with 5% CO2 and 95% air. Following incubation, the semi-hardened epithelium of each lens was carefully removed, fixed and processed for electron microscopic studies. Thin sections (60-70 mm) were contrasted with uranyl acetate and lead citrate and viewed under a transmission electron microscope. Normal epithelial cells showed intact, euchromatic nucleus with few small vacuoles (diameter 0.58+/-0.6 microm) in well-demarcated cytoplasm. After treatment with H2O2, they showed pyknotic nuclei with clumping of chromatin and ill-defined edges. The cytoplasm was full of vacuoles (diameter 1.61+/-0.7 microm). The overall cellular morphology was typical of dying cells. Treatment of cells with Ocimum sanctum extract protected the epithelial cells from H2O2 insult and maintained their normal architecture. The mean diameter of the vacuoles was 0.66+/-0.2 microm. The results indicate that extracts of O. sanctum have an important protective role against H2O2 injury in HLEC by maintaining the normal cellular architecture. The protection could be due to its ability to reduce H2O2 through its antioxidant property and thus reinforcing the concept that the extracts can penetrate the HLEC membrane....(more)
Halder N, et al. Phytother Res 2009 Dec;23(12):1734-7.
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- 4. Evaluation of cardioprotective activity of Ginkgo biloba and Ocimum sanctum in rodents.
This study investigates the cardioprotective activity of a combined treatment of Ginkgo biloba phytosomes (GBP) and Ocimum sanctum extract (Os) in isoproterenol (ISO)-induced myocardial necrosis in rats. Significant myocardial necrosis, depletion of the endogenous antioxidants superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), glutathione reductase (GR), and glutathione (GSH), and increases in the serum marker enzymes aspartate aminotransferase (AST), lactate dehydrogenase (LDH), and creatine phosphokinase (CPK) were observed in ISO-treated rats compared with normal rats. Co-administration of GBP (100 mg per kg) with Os at two doses (50 and 75 mg per kg) for 30 days to rats treated with ISO (85 mg per kg, sc) on the 29th and 30th days demonstrated a significant decrease in ISO-induced serum marker enzyme elevations and a significant attenuation of the ISO-elevated myocardial lipid peroxidation marker malondialdehyde (MDA). A significant restoration of ISO-depleted activities and levels of AST, LDH, CPK, GSH, SOD, CAT, GPx, and GR in the hearts of the treatment groups was observed. The combination of Os 75 mg per kg and GBP 100 mg/kg elicited greater protection than the combination of Os 50 mg per kg and GBP 100 mg per kg. It may be concluded that GBP-Os oral treatment to ISO-challenged rats demonstrates significant cardiac protection, decreases lipid peroxidation, and restores antioxidant activities. However, the combined treatment failed to enhance cardioprotective activity of either herb when used alone....(more)
Panda VS, et al. Altern Med Rev 2009 Jun;14(2):161-71.
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- 5. Prevention of insulin resistance by ingesting aqueous extract of Ocimum sanctum to fructose-fed rats.
The study was aimed to examine if oral administration of the aqueous extract of the whole plant OCIMUM SANCTUM (OS) protects against the development of insulin resistance in fructose fed rats. Male Wister rats were randomly divided into four groups of eight animals each: group-S (starch diet), group-F (fructose diet), group-F+OS (fructose diet along with OCIMUM SANCTUM extract at a dose of 200 mg/kg), group-S+OS (starch diet along with OCIMUM SANCTUM). During the experimental period of 60 days body weight, plasma glucose, insulin, and triglycerides were measured at an interval of 15 days. Insulin sensitivity was assessed at the end of experimental period by measuring glucose-insulin index, which is the product of the areas under the curve of glucose and insulin during oral glucose tolerance test. The nontoxic nature of OS was revealed by unaltered body weight, plasma glucose, insulin, and triglyceride levels in group-S+OS when compared with group-S. A significant gain in body weight, hyperglycemia, hyperinsulinemia, hypertriglyceridemia, and insulin resistance were observed in group-F when compared with group-S. OS treatment prevented the observed fructose induced alterations in group-F+OS. In conclusion, our results suggests that oral administration of OS aqueous extract could delay the development of insulin resistance in rats and may be used as an adjuvant therapy for treating diabetic patients with insulin resistance....(more)
Reddy SS, et al. Horm Metab Res 2008 Jan;40(1):44-9.
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- 6. Inhibition of telomerase activity by oleanane triterpenoid CDDO-Me in pancreatic cancer cells is ROS-dependent.
Methyl-2-cyano-3,12-dioxooleana-1,9(11)-dien-28-oate (CDDO-Me) is a synthetic derivative of oleanolic acid, a triterpene, with apoptosis-inducing activity in a wide range of cancer cells. Induction of apoptosis by CDDO-Me is associated with the generation of reactive oxygen species (ROS) and inhibition of telomerase activity. In the present study, we investigated the role of ROS in inhibition of telomerase by CDDO-me. Treatment of MiaPaCa-2 and Panc-1 pancreatic cancer cell lines with CDDO-Me induced the production of hydrogen peroxide and superoxide anions and inhibited the telomerase activity. Pretreatment of cells with N-acetylcycsteine, a general purpose antioxidant or overexpression of glutathione peroxidase (GPx) or superoxide dismutase-1 (SOD-1) blocked the telomerase inhibitory activity of CDDO-Me. Furthermore, blocking ROS generation also prevented the inhibition of hTERT gene expression, hTERT protein production and expression of a number of hTERT-regulatory proteins by CDDO-Me (e.g., c-Myc, Sp1, NF-κB and p-Akt). Data also showed that Akt plays an important role in the activation of telomerase activity. Together, these data suggest that inhibition of telomerase activity by CDDO-Me is mediated through a ROS-dependent mechanism; however, more work is needed to fully understand the role of ROS in down-regulation of hTERT gene and hTERT-regulatory proteins by CDDO-Me....(more)
Deeb D, et al. Molecules 2013 Mar 13;18(3):3250-65.
Related Products: Oleanolic Acid
- 7. Protective effect of oleanolic acid against beta cell dysfunction and mitochondrial apoptosis: crucial role of ERK-NRF2 signaling pathway.
Pancreatic beta cell dysfunction is a hallmark of diabetes. Our previous results have shown that oleanolic acid (OA) has anti-diabetic potential. However, there is little literature reporting the effect of OA on beta cell dysfunction. The present study was designed to investigate the protective effect of OA against lipotoxicity and the underlying mechanisms. Lepr (db/db) diabetic mice were subjected to fasting blood glucose measurement, intraperitoneal glucose tolerance test after the administration of OA for two weeks. Histopathological observation was conducted by HE staining and transmission electron microscopy assay. Pancreatic islets were isolated from db/db diabetic mice and C57BL/6J mice. Palmitic acid (PA) was used to induce lipotoxicity in vitro. Apoptosis was evaluated in pancreatic islets in diabetic mice and in isolated pancreatic islets and beta-TC3 cells by TUNEL assay. Cellular ATP content, mitochondrial function and redox balance were examined. Phosphorylation of c-Jun NH2-terminal kinase (JNK) and extracellular signal-regulated kinase (ERK) and the activation of nuclear erythroid factor 2 p45-related factor 2 (Nrf2) signaling were evaluated by western blotting. In db/db mice, OA significantly protects beta cell function against lipotoxicity, evidenced by inhibition of apoptosis and improvement of glucose tolerance. In cells, OA administration may protect against PA-induced apoptosis and decrease of GSIS, in which process the activation of Nrf2 is essential. Once Nrf2 is activated, OA could induce GCLc expression, promote the production of GSH, and thus inhibit JNK phosphorylation and solid the antioxidant defense of mitochondria, leading to the inhibition of mitochondrial apoptosis. ERK signaling pathway is responsible for OA-induced activation of Nrf2 and the protective effect of OA. Overall, our study enhances the understanding of the protective effect of OA on beta cell and provides clues for further studies on the underlying mechanisms....(more)
Wang X, et al. J Biol Regul Homeost Agents 2013 Jan-Mar;27(1):55-67.
Related Products: Oleanolic Acid
- 8. Lithium adduct as precursor ion for sensitive and rapid quantification of 20 (S)-protopanaxadiol in rat plasma by liquid chromatography/quadrupole linear ion trap mass spectrometry and application to rat pharmacokinetic study.
A novel, rapid and sensitive liquid chromatography/quadrupole linear ion trap mass spectrometry [LC-ESI-(QqLIT)MS/MS] method was developed and validated for the quantification of protopanaxadiol (PPD) in rat plasma. Oleanolic acid (OA) was used as internal standard (IS). A simple protein precipitation based on acetonitrile (ACN) was employed. Chromatographic separation was performed on a Sepax GP-C18 column (50 × 2.1 mm, 5 μM) with a mobile phase consisting of ACN-water and 1.5 μM formic acid and 25 mM lithium acetate (90 : 10, v/v) at a flow rate of 0.4 ml/min for 3.0 min. Multiple-reaction-monitoring mode was performed using lithium adduct ion as precursor ion of m/z 467.5/449.4 and 455.6/407.4 for the drug and IS, respectively. Calibration curve was recovered over a concentration range of 0.5-100 ng/ml with a correlation coefficient >0.99. The limit of detection was 0.2 ng/ml in rat plasma for PPD. The results of the intraday and interday precision and accuracy studies were well within the acceptable limits. The validated method was successfully applied to investigate the pharmacokinetic study of PPD after intravenous and gavage administration to rat....(more)
Bao Y, et al. J Mass Spectrom 2013 Mar;48(3):399-405.
Related Products: Oleanolic Acid
- 9. Identification of novel dietary phytochemicals inhibiting the efflux transporter breast cancer resistance protein (BCRP/ABCG2).
Breast cancer resistance protein (BCRP/ABCG2) plays an important role in determining the absorption and disposition of consumed xenobiotics including various drugs and dietary phytochemicals and is also one of the prominent efflux transporters involved in multidrug resistance (MDR). In this study, we have investigated the interactions between ABCG2 and 56 naturally-occurring phytochemicals including phenolic acids, flavonoids, triterpenes and other common dietary phytochemicals, as well as two non plant-based compounds (hippuric acid and propyl gallate) using cell- and membrane-based transport inhibition assays. Of the non-flavonoid phytochemicals tested, berberine, celastrol, ellagic acid, limonin, oleanolic acid, propyl gallate, sinapic acid and ursolic acid demonstrated significant inhibition of ABCG2-mediated transport. Chrysoeriol, laricitrin, myricetin 3',4',5'-trimethylether, pinocembrin, quercitrin, tamarixetin, tricetin and tricetin 3',4',5'-trimethylether were also identified as novel flavonoid ABCG2 inhibitors. The identified inhibitory activity of dietary phytochemicals on ABCG2 provides a framework for further investigation of ABCG2-modulated phytochemical bioavailability, MDR, and possible food-drug interactions....(more)
Tan KW, et al. Food Chem 2013 Jun 15;138(4):2267-74.
Related Products: Oleanolic Acid
- 10. Oleanolic acid acetate inhibits atopic dermatitis and allergic contact dermatitis in a murine model.
Atopic dermatitis (AD) and allergic contact dermatitis (ACD) are common allergic and inflammatory skin diseases caused by a combination of eczema, scratching, pruritus, and cutaneous sensitization with allergens. This paper examines whether oleanolic acid acetate (OAA) modulates AD and ACD symptoms by using an existing AD model based on the repeated local exposure of mite extract (Dermatophagoides farinae extract, DFE) and 2,4-dinitrochlorobenzene to the ears of BALB/c mice. In addition, the paper uses a 2,4-dinitrofluorobenzene-sensitized local lymph node assay (LLNA) for the ACD model. The oral administration of OAA over a four-week period attenuated AD symptoms in terms of decreased skin lesions, epidermal thickness, the infiltration of immune cells (CD4(+) cells, eosinophils, and mast cells), and serum IgE, IgG2a, and histamine levels. The gene expression of Th1, Th2, Th17, and Th22 cytokines was reduced by OAA in the lymph node and ear tissue, and the LLNA verified that OAA suppressed ACD. The oral administration of OAA over a three-day period attenuated ACD symptoms in terms of ear thickness, lymphocyte proliferation, and serum IgG2a levels. The gene expression of Th1, Th2, and Th17 cytokines was reduced by OAA in the thymus and ear tissue. Finally, to define the underlying mechanism, this paper uses a TNF-α/IFN-γ-activated human keratinocyte (HaCaT) model. OAA inhibited the expression of cytokines and chemokines through the downregulation of NF-κB and MAPKs in HaCaT cells. Taken together, the results indicate that OAA inhibited AD and ACD symptoms, suggesting that OAA may be effective in treating allergic skin disorders....(more)
Choi JK, et al. Toxicol Appl Pharmacol 2013 May 15;269(1):72-80.
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- 11. Mechanisms involved in the antinociceptive effects of orally administered oleanolic acid in the mouse.
The antinociceptive effects of oleanolic acid were examined in ICR mice. Oleanolic acid administered orally (1, 5 and 10 mg/kg) showed an antinociceptive effect in a dose-dependent manner as measured in the acetic acid-induced writhing test. In the time- course study, duration of antinociceptive action of oleanolic acid maintained at least for 60 min. In addition, the cumulative nociceptive response time for intraplantar formalin injection (2nd phase), intrathecal injection of substance P (0.7 μg) or glutamate (20 μg) was diminished by oleanolic acid. Intraperitoneal (i.p.) pretreatment with naloxone (opioid receptor antagonist) or methysergide (5-HT serotonergic receptor antagonist) attenuated antinociceptive effect induced by oleanolic acid in the writhing test. However, yohimbine (adrenergic receptor antagonist) did not affect antinociception induced by oleanolic acid. The results indicate that oleanolic acid shows an antinociceptive property in various pain models such as writhing, formalin, substance P and glutamate pain tests. Furthermore, this antinociceptive effect of oleanolic acid may be mediated by opioidergic and serotonergic receptors, but not adrenergic receptors....(more)
Park SH, et al. Arch Pharm Res 2013 Mar 21.
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- 12. Efficient synthesis and anti-fungal activity of oleanolic acid oxime esters.
In order to develop potential glucosamine-6-phosphate synthase inhibitors and anti-fungal agents, twenty five oleanolic acid oxime esters were synthesized in an efficient way. The structures of the new compounds were confirmed by MS, HRMS, 1H-NMR and 13C-NMR. Preliminary studies based on means of the Elson-Morgan method indicated that many compounds exhibited some inhibitory activity of glucosamine-6-phosphate synthase (GlmS), and the original fungicidal activities results showed that some of the compounds exhibited good fungicidal activities towards Sclerotinia sclerotiorum (Lib.) de Bary, Rhizoctonia solani Kuhn and Botrytis cinerea Pers at the concentration of 50 µg/mL. These compounds would thus merit further study and development as antifungal agents....(more)
Zhao H, et al. Molecules 2013 Mar 21;18(3):3615-29.
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- 13. Efficient and Scalable Synthesis of Bardoxolone Methyl (CDDO-methyl Ester).
Bardoxolone methyl (2-cyano-3,12-dioxooleane-1,9(11)-dien-28-oic acid methyl ester; CDDO-Me) (1), a synthetic oleanane triterpenoid with highly potent anti-inflammatory activity (levels below 1 nM), has completed a successful phase I clinical trial for the treatment of cancer and a successful phase II trial for the treatment of chronic kidney disease in type 2 diabetes patients. Our synthesis of bardoxolone methyl (1) proceeds in ∼50% overall yield in five steps from oleanolic acid (2), requires only one to two chromatographic purifications, and can provide gram quantities of 1....(more)
Fu L, et al. Org Lett 2013 Mar 26.
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- 14. Synthesis and biological evaluation of oleanolic acid derivatives as PTP1B inhibitors.
Twenty-four sugar-substituted oleanolic acid derivatives (1a-1f, 2a-2j, and 3a-3h) were synthesized in a concise and efficient strategy and their effects on the inhibition of protein tyrosine phosphatase 1B (PTP1B) and insulin-sensitizing response were evaluated in vitro. Several derivatives showed moderate to good inhibitory activities against PTP1B, and especially compounds 2f, 2h, 3d and 3e exhibited the most potent inhibitory activities with the IC50 values of 1.91, 12.2, 9.21 and 0.56 μM against PTP1B, respectively. Furthermore, compounds 2g-2h and 3b-3e displayed good insulin-sensitizing activities with the response values ranging from 21.52% to 59.58%. Structure-activity relationship study of these sugar-substituted oleanolic acid derivatives demonstrated that PTP1B inhibitory activity and insulin-sensitizing response were strongly influenced by both the carbohydrate moiety at the C-3 position and the long acidic chain at C-28 position of oleanolic acid....(more)
Liu QC, et al. Eur J Med Chem 2013 Mar 14;63C:511-522.
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- 15. Chemical Characterization and In Vivo Anti-Inflammatory Activities of Actinidia callosa var. ephippioides via Suppression of Proinflammatory Cytokines.
Actinidia callosa var. ephippioides (ACE) has been widely used to treat anti-pyretic, antinociceptive, anti-inflammation, abdominal pain and fever in Taiwan. This study aims to determine the mechanism of anti-inflammatory activities of ethyl acetate fraction of ACE (EA-ACE) using a model of λ-carrageenan (Carr)-induced paw edema in mouse model. In HPLC analysis, chemical characterization of EA-ACE was established. In order to investigate the anti-inflammatory mechanism of EA-ACE, we have detected the activities of catalase (CAT), superoxide dismutase (SOD), and glutathione peroxidase (GPx) and the levels of malondialdehyde (MDA) in the paw edema. Serum NO, tumor necrosis factor α (TNF-α), and interleukin-1β (IL-1β) were evaluated. Chemical characterization from HPLC indicated that EA-ACE contains betulinic acid, ursolic acid and oleanolic acid. In the anti-inflammatory test, EA-ACE decreased the paw edema after Carr administration, increased the activities of CAT, SOD, and GPx and decreased the MDA level in the edema paw at the 5th hr after Carr injection. EA-ACE affects the serum NO, TNF-α, and IL-1β levels at the 5th hr after Carr injection. EA-ACE decreased Carr-induced inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) expressions by Western blotting. Actinidia callosa var. ephippioides have the potential to provide a therapeutic approach to inflammation-associated disorders....(more)
Liao JC, et al. Am J Chin Med 2013;41(2):405-23.
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- 16. Effects of a polyphenol present in olive oil, oleuropein aglycone, in a murine model of intestinal ischemia/reperfusion injury.
Dietary olive oil supplementation and more recently, olive oil phenols have been recommended as important therapeutic interventions in preventive medicine. Ole has several pharmacological properties, including antioxidant, anti-inflammatory, antiatherogenic, anticancer, antimicrobial, and antiviral and for these reasons, is becoming an important subject of study in recent years. The aim of this study was to investigate the effects of Ole aglycone on the modulation of the secondary events in mice subjected to intestinal IRI. This was induced in mice by clamping the superior mesenteric artery and the celiac trunk for 30 min, followed by release of the clamp, allowing reperfusion for 1 h. After 60 min of reperfusion, animals were killed for histological examination of the ileum tissue and immunohistochemical localization of proinflammatory cytokines (TNF-α and IL-1β) and adhesion molecules (ICAM-1 and P-sel); moreover, by Western blot analysis, we investigated the activation of NF-κB and IκBα. In addition, we evaluated the apoptosis process, as shown by TUNEL staining and Bax/Bcl-2 expressions. The results obtained by the histological and molecular examinations showed in Ole aglycone-treated mice, a decrease of inflammation and apoptosis pathway versus SAO-shocked mice. In conclusion, we propose that the olive oil compounds, in particular, the Ole aglycone, could represent a possible treatment against secondary events of intestinal IRI....(more)
Campolo M, et al. J Leukoc Biol 2013 Feb;93(2):277-87.
Related Products: Oleuropein
- 17. Olive oil oleuropein has anti-breast cancer properties with higher efficiency on ER-negative cells.
Breast cancer constitutes a major health problem for women worldwide. However, its incidence varies between populations and geographical locations. These variations could be diet-related, since there are several carcinogenic compounds in the modern diet, while natural products contain various anti-cancer elements. Several lines of evidence indicate that, in addition to their clear preventive effect, these compounds could also be used as therapeutic agents. In the present report we have shown that oleuropein, a pharmacologically safe natural product of olive leaf, has potent anti-breast cancer properties. Indeed, oleuropein exhibits specific cytotoxicity against breast cancer cells, with higher effect on the basal-like MDA-MB-231 cells than on the luminal MCF-7 cells. This effect is mediated through the induction of apoptosis via the mitochondrial pathway. Moreover, oleuropein inhibits cell proliferation by delaying the cell cycle at S phase and up-regulated the cyclin-dependent inhibitor p21. Furthermore, oleuropein inhibited the anti-apoptosis and pro-proliferation protein NF-κB and its main oncogenic target cyclin D1. This inhibition could explain the great effect of oleuropein on cell proliferation and cell death of breast cancer cells. Therefore, oleuropein warrants further investigations to prove its utility in preventing/treating breast cancer, especially the less-responsive basal-like type....(more)
Elamin MH, et al. Food Chem Toxicol 2013 Mar;53:310-6.
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- 18. Leishmanicidal activity assessment of olive tree extracts.
Leishmaniasis, a protozoan parasitic disease that remains a major worldwide health problem with high endemicity in developing countries, is prevalent around the Mediterranean basin. High cost, systemic toxicity, and diminished efficacy due to development of parasite resistance are the serious drawbacks of current treatment options. Thus, identifying new, effective, and safer anti-leishmanial drug(s) is of paramount importance. Here we tested the anti-promastigote and anti-amastigote activity of five natural products, including oleuropein and hydroxytyrosol, present in olive tree leaves and olive mill wastewater. These products are recognized as low-cost starting materials rich in bioactive compounds, particularly biophenols. Oleuropein and hydroxytyrosol exhibited the best inhibitory effect among the natural products tested in both stationary and middle logarithmic phase promastigotes of L. infantum, L. donovani, and L. major. Similarly, oleuropein and hydroxytyrosol demonstrated the highest selectivity index ratio against L. donovani amastigotes that parasitize J774A.1 macrophages. Moreover, oleuropein was tested in vivo in an experimental visceral leishmaniasis model. L. donovani-infected BALB/c mice received intraperitoneal oleuropein a total of 14 times at intervals of every other day. Three days after treatment termination, the spleen parasitic burden was reduced >80%. Of interest, this effect of oleuropein persisted and was even enhanced 6 weeks after the termination of the treatment, as determined by parasite depletion of >95% in liver and spleen. These findings contribute to the potential development of natural products as effective drugs against parasites of the Leishmania genus, with low cost and diminished cytotoxicity....(more)
Kyriazis JD, et al. Phytomedicine 2013 Feb 15;20(3-4):275-81.
Related Products: Oleuropein
- 19. Hydrogen bonding probes of phenol -OH groups.
Correlations between hydrogen bonds and solvent effects on phenol -OH proton shieldings, temperature coefficients (Δδ/ΔT) and effects on OH diffusion coefficients for numerous phenolic acids, flavonols, flavones, and oleuropein derivatives of biological interest were investigated in several organic solvents and were shown to serve as reliable indicators of hydrogen bonding and solvation state of -OH groups. The temperature coefficients span a range of -0.5 to -12.3 ppb K(-1). Shielding differences of 2.0 to 2.9 ppm at 298 K were observed for solvent exposed OH groups between DMSO-d(6) and CD(3)CN which should be compared with a shielding range of ~7 ppm. This demonstrates that the solvation state of hydroxyl protons is a key factor in determining the value of the chemical shift. For -OH protons showing temperature gradients more positive than -2.5 ppb K(-1), shielding changes between DMSO-d(6) and CD(3)CN below 0.6 ppm, and diffusion coefficients significantly different from those of traces of H(2)O, there is an intramolecular hydrogen bond predictivity value of 100%. The C-3 OH protons of flavonols show very significant negative temperature coefficients and shielding changes between DMSO-d(6) and CD(3)CN of ~2.3 ppm, which indicate the absence of persistent intramolecular hydrogen bonds, contrary to numerous X-ray structures....(more)
Kontogianni VG, et al. Org Biomol Chem 2013 Feb 14;11(6):1013-25.
Related Products: Oleuropein
- 20. Oleuropein, a secoiridoid derived from olive tree, inhibits the proliferation of human colorectal cancer cell through downregulation of HIF-1α.
Oleuropein (OL) is the most prominent phenolic compound in the fruit of olive tree. Although OL has shown powerful anticancer activity the underlying action mechanism remains largely unknown. The present study evaluated the effects of OL on hydroxityrosol (HT)-29 human colon adenocarcinoma cells in comparison to hydroxytyrosol, its hydrolysis product, and to elucidate the underlying anticancer molecular mechanisms involved. Cell proliferation was determined using SRB assay. Cell cycle and apoptosis were assessed by flow cytometry and changes in MAPK cascade protein expression, HIF-1α, p53, PPARγ, and NFKβ signaling pathways by Western blot. Although OL showed less potency than HT, in terms of cell growth inhibition, induced significant changes in cell cycle analysis and caused a significant increase in the apoptotic population. Both compounds produced a remarkable decrease in HIF-1α protein and an upregulation of p53 protein expression. However, no significant changes in IkB-α and MAPK cascade protein expressions were observed. HT produced a significant upregulation in peroxisome proliferator-activated receptor gamma (PPARγ) expression whereas OL failed. PPARγ upregulation may be one of the principal mechanisms of the tumor shrinkage by HT. Our novel findings demonstrate that OL limits the growth and induces apoptosis in HT-29 cells via p53 pathway activation adapting the HIF-1α response to hypoxia....(more)
Cárdeno A, et al. Nutr Cancer 2013;65(1):147-56.
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- 21. Xenohormetic and anti-aging activity of secoiridoid polyphenols present in extra virgin olive oil: a new family of gerosuppressant agents.
Aging can be viewed as a quasi-programmed phenomenon driven by the overactivation of the nutrient-sensing mTOR gerogene. mTOR-driven aging can be triggered or accelerated by a decline or loss of responsiveness to activation of the energy-sensing protein AMPK, a critical gerosuppressor of mTOR. The occurrence of age-related diseases, therefore, reflects the synergistic interaction between our evolutionary path to sedentarism, which chronically increases a number of mTOR activating gero-promoters (e.g., food, growth factors, cytokines and insulin) and the "defective design" of central metabolic integrators such as mTOR and AMPK. Our laboratories at the Bioactive Food Component Platform in Spain have initiated a systematic approach to molecularly elucidate and clinically explore whether the "xenohormesis hypothesis," which states that stress-induced synthesis of plant polyphenols and many other phytochemicals provides an environmental chemical signature that upregulates stress-resistance pathways in plant consumers, can be explained in terms of the reactivity of the AMPK/mTOR-axis to so-called xenohormetins. Here, we explore the AMPK/mTOR-xenohormetic nature of complex polyphenols naturally present in extra virgin olive oil (EVOO), a pivotal component of the Mediterranean style diet that has been repeatedly associated with a reduction in age-related morbid conditions and longer life expectancy. Using crude EVOO phenolic extracts highly enriched in the secoiridoids oleuropein aglycon and decarboxymethyl oleuropein aglycon, we show for the first time that (1) the anticancer activity of EVOO secoiridoids is related to the activation of anti-aging/cellular stress-like gene signatures, including endoplasmic reticulum (ER) stress and the unfolded protein response, spermidine and polyamine metabolism, sirtuin-1 (SIRT1) and NRF2 signaling; (2) EVOO secoiridoids activate AMPK and suppress crucial genes involved in the Warburg effect and the self-renewal capacity of "immortal" cancer stem cells; (3) EVOO secoiridoids prevent age-related changes in the cell size, morphological heterogeneity, arrayed cell arrangement and senescence-associated β-galactosidase staining of normal diploid human fibroblasts at the end of their proliferative lifespans. EVOO secoiridoids, which provide an effective defense against plant attack by herbivores and pathogens, are bona fide xenohormetins that are able to activate the gerosuppressor AMPK and trigger numerous resveratrol-like anti-aging transcriptomic signatures. As such, EVOO secoiridoids constitute a new family of plant-produced gerosuppressant agents that molecularly "repair" the aimless (and harmful) AMPK/mTOR-driven quasi-program that leads to aging and aging-related diseases, including cancer....(more)
Menendez JA, et al. Cell Cycle 2013 Feb 15;12(4):555-78.
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- 22. Inhibition of 6-Hydroxydopamine-Induced PC12 Cell Apoptosis by Olive (Olea europaea L.) Leaf Extract Is Performed by Its Main Component Oleuropein.
Abstract Parkinson disease (PD) is the most common progressive neurodegenerative disorder characterized by progressive death of midbrain dopaminergic neurons. Most neurodegenerative disease treatments are, at present, palliative. However, some natural herbal products have been shown to rescue neurons from death and apoptosis in some of neurodegenerative diseases. Not only Olea europaea L. olive oil, but also the leaves of this plant have been used for medical purposes. Olive leaf extract (OLE) is being used by people as a drink across the world and as an integral ingredient in their desire to maintain and improve their health. Here, we investigated the effects of OLE and its main phenolic component oleuropein on 6-hydroxydopamine (6-OHDA)-induced toxicity in rat adrenal pheochromocytoma (PC12) cells as an in vitro model of PD. Cell damage was induced by 150 μM 6-OHDA. The cell survival rate was examined by MTT assay. Generation of intra-cellular reactive oxygen species (ROS) was studied using fluorescence spectrophotometry. Immunoblotting and DNA analysis were also employed to determine the levels of biochemical markers of apoptosis in the cells. The data showed that 6-OHDA could decrease the viability of the cells. In addition, intra-cellular ROS, activated caspase 3, Bax/Bcl-2 ratio, as well as DNA fragmentation were significantly increased in 6-OHDA-treated cells. Incubation of cells with OLE (400 and 600 μg/mL) and oleuropein (20 and 25 μg/mL) could decrease cell damage and reduce biochemical markers of cell death. The results suggest that OLE and oleuropein have anti-oxidant protective effects against 6-OHDA-induced PC12 cell damage. The protective effects of OLE and oleuropein are correlative with their anti-oxidative and anti-apoptotic properties and suggest their therapeutic potential in the treatment of PD....(more)
Pasban-Aliabadi H, et al. Rejuvenation Res 2013 Apr;16(2):134-42.
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- 23. A validated method for the determination of selected phenolics in olive oil using high-performance liquid chromatography with coulometric electrochemical detection and a fused-core column.
A liquid chromatographic method with a coulometric electrochemical detector (ECD) and a fused-core column was developed for the quantification of the olive oil phenolics tyrosol, hydroxytyrosol, oleuropein, pinoresinol, and caffeic, ferulic, vanillic, and p-coumaric acid. The method was validated according to guidelines of the U.S. Food and Drug Administration. The selectivity, linearity, lower limit of quantification (LOQ), lower limit of detection (LOD), precision, accuracy, recovery, as well as the stabilities of the phenolic standards and quality control samples were determined. The separation of the eight phenolic compounds was achieved within 16 min and the total analysis time (35 min) was ca. 3-fold shorter than that of conventional HPLC methods. The LOQ range was 0.3-15.3 ng/mL, which is at least 5-fold lower than those of other methods. Recovery was between 75% and 101%. Overall the method has the advantages of being sensitive, selective, fast and provides simultaneous qualitative and quantitative analysis of phenolics....(more)
Bayram B, et al. Food Chem 2013 Jun 1;138(2-3):1663-9.
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- 24. Combined effect of starter culture and temperature on phenolic compounds during fermentation of Taggiasca black olives.
The influence of two operative parameters on the fermentation process of table olives from Taggiasca cultivar were investigated. Laboratory scale fermentations were performed using Lactobacillus plantarum as the only starter and in combination with Saccharomyces cerevisiae at three different temperatures (23, 30 and 37°C). Control tests used for each trial were fermented only by indigenous microflora. pH and phenolic compounds were monitored in the brine and olive flesh during the fermentation. Higher temperatures (37°C) enhanced notably the release of phenolic compounds in the brine. High performance liquid chromatography (HPLC) analysis of brines evidenced the complete hydrolysis of oleuropein after 100 days of fermentation at 37°C for all treatments. The antioxidant power of the extracts was linearly correlated to their polyphenol contents. The results confirmed the efficiency of treatments compared with the control tests for debittering process of table black olives. Phenolic compounds in the brines can be then extracted and used in food, cosmetic and pharmaceutical industries....(more)
Pistarino E, et al. Food Chem 2013 Jun 1;138(2-3):2043-9.
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- 25. Hydrothermal carbonization of olive mill wastewater.
Hydrothermal carbonization (HTC) is an emerging technology to treat wet biomasses aimed at producing a biochar material. Herein, olive mill wastewater (OMW) was subjected to HTC. Mass balance considerations provide evidence that the yield of biochar is low (∼30%, w/w), which is associated with a low fraction of carbohydrates in OMW. The combination of different preparation schemes, pre-chromatographic derivatization reactions and GC/MS analysis for the analysis of organic compounds in aqueous HTC-solutions allowed to identify and quantify a wide array of analytes which belong either to intrinsic constituents of OMW or to characteristic HTC-breakdown products. Biophenols, such as hydroxyl-tyrosol (OH-Tyr), tyrosol (Tyr) account for the most abundant members of the first group. Most abundant breakdown products include phenol and benzenediols as well as short-chain organic acids. Secoiridoids, such as decarbomethoxy ligostride aglycon and decarbomethoxy oleuropein aglycon, all of them being typical components of OMW, are less abundant in HTC-solutions....(more)
Poerschmann J, et al. Bioresour Technol 2013 Apr;133:581-8.
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- 26. Optimization of olive leaf extract obtained by ultrasound-assisted extraction with response surface methodology.
In the present article, ultrasound-assisted extraction (UAE) of polyphenols from agricultural and industrial waste of olive oil and table oil productions, olive tree (Olea europaea) leaves were investigated. The aim of the study is to examine the extraction parameters such as solvent concentration (0-100% ethanol (EtOH), v/v), the ratio of solid to solvent (25-50mg/mL) and extraction time (20-60 min), and to obtain the best possible combinations of these parameters through response surface methodology (RSM). The extract yield was stated as mg extract per g of dried leaf (DL). Total phenolic content was expressed in gallic acid equivalent (GAE) per g of dried leaf. Free radical scavenging activity for the antioxidant capacity was tested by 1,1-diphenyl-2-picryl hydrazyl (DPPH) radical. The second order polynomial model gave a satisfactory description of the experimental data. 201.2158 mg extract/g DL, 25.0626 mg GAE/g DL, and 95.5610% in respect to inhibition of DPPH radical were predicted at the optimum operating conditions (500 mg solid to 10 mL solvent ratio, 60 min of extraction time and 50% EtOH composition), respectively....(more)
?ahin S, et al. Ultrason Sonochem 2013 Jan;20(1):595-602.
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- 27. A metabolite-profiling approach to assess the uptake and metabolism of phenolic compounds from olive leaves in SKBR3 cells by HPLC-ESI-QTOF-MS.
Olive leaves, an easily available natural low-cost material, constitute a source of extracts with significant antitumor activity that inhibits cell proliferation in several breast-cancer-cell models. In this work, a metabolite-profiling approach has been used to assess the uptake and metabolism of phenolic compounds from an olive-leaf extract in the breast-cancer-cell line SKBR3 to evaluate the compound or compounds responsible for the cytotoxic activity. For this, the extract was firstly characterized quantitatively by high-performance liquid chromatography coupled to electrospray ionization-quadrupole time-of-flight mass spectrometry (HPLC-ESI-QTOF-MS). Then, SKBR3 cells were incubated with 200 μg/mL of the olive-leaf extract at different times (15 min, 1, 2, 24, and 48 h). A metabolite-profiling approach based on HPLC-ESI-QTOF-MS was used to determine the intracellular phenolic compounds, enabling the identification of 16 intact phenolic compounds from the extract and four metabolites derived from these compounds in the cell cytoplasm. The major compounds found within the cells were oleuropein, luteolin-7-O-glucoside and its metabolites luteolin aglycone and methyl-luteolin glucoside, as well as apigenin, and verbascoside. Neither hydroxytyrosol nor any of its metabolites were found within the cells at any incubation time. It is proposed that the major compounds responsible for the cytotoxic activity of the olive-leaf extract in SKBR3 cells are oleuropein and the flavones luteolin and apigenin, since these compounds showed high uptake and their antitumor activity has been previously reported....(more)
Quirantes-Piné R, et al. J Pharm Biomed Anal 2013 Jan;72:121-6.
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- 28. Inhibition of 6-Hydroxydopamine-Induced PC12 Cell Apoptosis by Olive (Olea europaea L.) Leaf Extract Is Performed by Its Main Component Oleuropein.
Abstract Parkinson disease (PD) is the most common progressive neurodegenerative disorder characterized by progressive death of midbrain dopaminergic neurons. Most neurodegenerative disease treatments are, at present, palliative. However, some natural herbal products have been shown to rescue neurons from death and apoptosis in some of neurodegenerative diseases. Not only Olea europaea L. olive oil, but also the leaves of this plant have been used for medical purposes. Olive leaf extract (OLE) is being used by people as a drink across the world and as an integral ingredient in their desire to maintain and improve their health. Here, we investigated the effects of OLE and its main phenolic component oleuropein on 6-hydroxydopamine (6-OHDA)-induced toxicity in rat adrenal pheochromocytoma (PC12) cells as an in vitro model of PD. Cell damage was induced by 150 μM 6-OHDA. The cell survival rate was examined by MTT assay. Generation of intra-cellular reactive oxygen species (ROS) was studied using fluorescence spectrophotometry. Immunoblotting and DNA analysis were also employed to determine the levels of biochemical markers of apoptosis in the cells. The data showed that 6-OHDA could decrease the viability of the cells. In addition, intra-cellular ROS, activated caspase 3, Bax/Bcl-2 ratio, as well as DNA fragmentation were significantly increased in 6-OHDA-treated cells. Incubation of cells with OLE (400 and 600 μg/mL) and oleuropein (20 and 25 μg/mL) could decrease cell damage and reduce biochemical markers of cell death. The results suggest that OLE and oleuropein have anti-oxidant protective effects against 6-OHDA-induced PC12 cell damage. The protective effects of OLE and oleuropein are correlative with their anti-oxidative and anti-apoptotic properties and suggest their therapeutic potential in the treatment of PD....(more)
Pasban-Aliabadi H, et al. Rejuvenation Res 2013 Apr;16(2):134-42.
Related Products: Olive Leaf Extract
- 29. Olive (Olea europaea L.) leaf polyphenols improve insulin sensitivity in middle-aged overweight men: a randomized, placebo-controlled, crossover trial.
BACKGROUND:
Olive plant leaves (Olea europaea L.) have been used for centuries in folk medicine to treat diabetes, but there are very limited data examining the effects of olive polyphenols on glucose homeostasis in humans.
OBJECTIVE:
To assess the effects of supplementation with olive leaf polyphenols (51.1 mg oleuropein, 9.7 mg hydroxytyrosol per day) on insulin action and cardiovascular risk factors in middle-aged overweight men.
DESIGN:
Randomized, double-blinded, placebo-controlled, crossover trial in New Zealand. 46 participants (aged 46.4 ± 5.5 years and BMI 28.0 ± 2.0 kg/m(2)) were randomized to receive capsules with olive leaf extract (OLE) or placebo for 12 weeks, crossing over to other treatment after a 6-week washout. Primary outcome was insulin sensitivity (Matsuda method). Secondary outcomes included glucose and insulin profiles, cytokines, lipid profile, body composition, 24-hour ambulatory blood pressure, and carotid intima-media thickness.
RESULTS:
Treatment evaluations were based on the intention-to-treat principle. All participants took >96% of prescribed capsules. OLE supplementation was associated with a 15% improvement in insulin sensitivity (p = 0.024) compared to placebo. There was also a 28% improvement in pancreatic β-cell responsiveness (p = 0.013). OLE supplementation also led to increased fasting interleukin-6 (p = 0.014), IGFBP-1 (p = 0.024), and IGFBP-2 (p = 0.015) concentrations. There were however, no effects on interleukin-8, TNF-α, ultra-sensitive CRP, lipid profile, ambulatory blood pressure, body composition, carotid intima-media thickness, or liver function.
CONCLUSIONS:
Supplementation with olive leaf polyphenols for 12 weeks significantly improved insulin sensitivity and pancreatic β-cell secretory capacity in overweight middle-aged men at risk of developing the metabolic syndrome....(more)
de Bock M, et al. PLoS One 2013;8(3):e57622.
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- 30. Mechanisms of olive leaf extract-ameliorated rat arthritis caused by kaolin and carrageenan.
Olive leaf extract (OLE) has antioxidant and antiinflammatory actions. However, the role of OLE in mechanical inflammatory arthritis (osteoarthritis, OA) is unclear. This study investigated the effect of OLE on the development of kaolin and carrageenan-induced arthritis, a murine model of OA. Administration of OLE significantly ameliorated paw swelling, the paw Evans blue content and the histopathological scores. In the human monocyte cell line, THP-1, the OLE reduced the LPS-induced TNF-α production and was dose dependent. Croton oil-induced ear edema in mice also revealed that treatment with OLE suppressed ear edema, myeloperoxidase (MPO) production and was dose dependent. These results indicated that OLE is an effective antiarthritis agent through an antiinflammation mechanism. Also OLE may be beneficial for the treatment of OA in humans....(more)
Gong D, et al. Phytother Res 2012 Mar;26(3):397-402.
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- 31. Inhibitory effect of olive leaf extract on gentamicin-induced nephrotoxicity in rats.
INTRODUCTION:
Gentamicin sulphate nephrotoxicity seems to be attributed to the generation of reactive oxygen species. Olive leaf extract (OLE) has been demonstrated to have antioxidant and anti-inflammatory effects. The aim of this study was to evaluate the inhibitory effect of OLE on gentamicin-induced nephrotoxicity in rats.
MATERIALS AND METHODS:
Thirty-five Sprague-dawley rats were divided into 5 groups to receive saline; gentamicin, 100 mg/kg/d; and gentamicin plus OLE in 3 different doses (25 mg/kg/d, 50 mg/kg/d, and 100 mg/kg/d, once daily for 12 days. Serum and renal malondialdehyde were assessed, and tubular necrosis was studied semiquantitatively. Glomerular volume and volume density of the proximal convoluted tubules were estimated stereologically from paraffin sections. Serum creatinine and renal antioxidant enzymes activity were measured.
RESULTS:
Gentamicin significantly increased serum creatinine, malondialdehyde, and tubular necrosis, and decreased creatinine clearance, volume density of the proximal convoluted tubules, renal glutathione, glutathione peroxidase, catalase, and superoxide dismutase compared with the control group. Cotreatment of gentamicin and OLE significantly decreased serum creatinine, malondialdehyde, tubular necrosis, and renal malondialdehyde, and increased renal glutathione, catalase, superoxide dismutase, volume density of proximal convoluted tubules, and creatinine clearance in comparison with gentamicin-only treated group. Serum malondialdehyde, serum creatinine, tubular necrosis, and volume density of proximal convoluted tubules were maintained at the same level as that of the control group by cotreatment of gentamicin and OLE.
CONCLUSIONS:
Olive leaf extract ameliorates gentamicin nephrotoxicity via antioxidant activity, increase of renal glutathione content, and increase of renal antioxidant enzymes activity, except for glutathione peroxidase....(more)
Tavafi M, et al. Iran J Kidney Dis 2012 Jan;6(1):25-32.
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- 32. Olive leaf extract modulates permethrin induced genetic and oxidative damage in rats.
Permethrin is a common synthetic chemical, widely used as an insecticide in agriculture and other domestic applications. The previous reports indicated that permethrin is a highly toxic synthetic pyrethroid pesticide to human and environmental health. Therefore, the present experiment was undertaken to determine the effectiveness of olive leaf extract in modulating the permethrin induced genotoxic and oxidative damage in rats. The animals used were broadly divided into four (A, B, C and D) experimental groups. Group A rats served as control animals and received distilled water intraperitoneally (n = 5). Groups B and C rats received intraperitoneal injections of permethrin (60 mg kg(-1) b.w) and olive leaf extract (500 mg kg(-1) b.w), respectively. Group D rats received permethrin (60 mg kg(-1) b.w) plus olive leaf extract (500 mg kg(-1) b.w). Rats were orally administered their respective feed daily for 21 days. At the end of the experiment rats were anesthetized and serum and bone marrow cell samples were obtained. Genotoxic damage was assessed by micronucleus and chromosomal aberration assays. Total antioxidant capacity and total oxidant status were also measured in serum samples to assess oxidative status. Treatment of Group B with permethrin resulted in genotoxic damage and increased total oxidant status levels. Permethrin treatment also significantly decreased (P < 0.05) total antioxidant capacity level when compared to Group A rats. Group C rats showed significant increases (P < 0.05) in total antioxidant capacity level and no alterations in cytogenetic parameters. Moreover, simultaneous treatments with olive leaf extract significantly modulated the toxic effects of permethrin in Group D rats. It can be concluded that olive leaf extract has beneficial influences and could be able to antagonize permethrin toxicity. As a result, this investigation clearly revealed the protective role of olive leaf extract against the genetic and oxidative damage by permethrin in vivo for the first time....(more)
Turkez H, et al. Cytotechnology 2012 Aug;64(4):459-64.
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- 33. Oleuropein, chief constituent of olive leaf extract, prevents the development of morphine antinociceptive tolerance through inhibition of morphine-induced L-type calcium channel overexpression.
It has been shown that blockade of L-type calcium channels could abolish the development of opioid-induced antinociceptive tolerance. Here, the antitolerant effects of olive leaf extract (OLE) and its main component, oleuropein, which have a calcium channel blocker property were determined. Adult male Wistar rats were injected with morphine (20 mg/kg, i.p.) for 8 days to induce antinociceptive tolerance. Then OLE (50-200 mg/kg i.g.) and oleuropein (1-10 mg/kg i.p.) were injected concomitantly with morphine. The tail-flick test was used to assess the nociceptive threshold. The dorsal half of the lumbar spinal cord was assayed for the expression of L-type calcium channel using semiquantitative RT-PCR. The results showed that OLE (200 mg/kg) completely prevented morphine tolerance development. In addition, oleuropein in dose of 10 mg/kg, but not in 5 mg/kg, prevented the development of morphine antinociceptive tolerance. In addition, a significant increase in the mRNA levels of calcium channel (43.9%) was observed in the lumbar spinal cord of tolerant animals, which was reversed by effective of dose OLE. In conclusion, the results indicate that olive leaf extract has a potential antitolerant property against the chronic usage of morphine and that its main component, oleuropein, is responsible for such effect....(more)
Zare L, et al. Phytother Res 2012 Nov;26(11):1731-7.
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- 34. Olive leaf extract as a hypoglycemic agent in both human diabetic subjects and in rats.
Olive tree (Olea europaea L.) leaves have been widely used in traditional remedies in European and Mediterranean countries as extracts, herbal teas, and powder. They contain several potentially bioactive compounds that may have hypoglycemic properties. To examine the efficacy of 500 mg oral olive leaf extract taken once daily in tablet form versus matching placebo in improving glucose homeostasis in adults with type 2 diabetes (T2DM). In this controlled clinical trial, 79 adults with T2DM were randomized to treatment with 500 mg olive leaf extract tablet taken orally once daily or matching placebo. The study duration was 14 weeks. Measures of glucose homeostasis including Hba1c and plasma insulin were measured and compared by treatment assignment. In a series of animal models, normal, streptozotocin (STZ) diabetic, and sand rats were used in the inverted sac model to determine the mechanism through which olive leaf extract affected starch digestion and absorption. In the randomized clinical trial, the subjects treated with olive leaf extract exhibited significantly lower HbA1c and fasting plasma insulin levels; however, postprandial plasma insulin levels did not differ significantly by treatment group. In the animal models, normal and STZ diabetic rats exhibited significantly reduced starch digestion and absorption after treatment with olive leaf extract compared with intestine without olive leaf treatment. Reduced digestion and absorption was observed in both the mucosal and serosal sides of the intestine. Though reduced, the decline in starch digestion and absorption did not reach statistical significance in the sand rats. Olive leaf extract is associated with improved glucose homeostasis in humans. Animal models indicate that this may be facilitated through the reduction of starch digestion and absorption. Olive leaf extract may represent an effective adjunct therapy that normalizes glucose homeostasis in individuals with diabetes....(more)
Wainstein J, et al. J Med Food 2012 Jul;15(7):605-10.
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- 35. Oleuropein prevents ethanol-induced gastric ulcers via elevation of antioxidant enzyme activities in rats.
Purified oleuropein from olive leaf extract has been shown to have antioxidant effects in our recent studies. Thus, the aim of this study was to assess the antioxidant abilities of oleuropein in comparison with ranitidine in ethanol-induced gastric damages via evaluation of ulcer index inhibition, antioxidant enzyme activities, and lipid peroxidation level. Fifty-six adult male Sprague-Dawley rats were divided into seven equal groups as follows: control group, ethanol group (absolute ethanol 1 ml/rat), oleuropein group (12 mg/kg), and oleuropein (6, 12, and 18 mg/kg) plus ethanol groups, as well as ranitidine (50 mg/kg) plus ethanol group. Pretreatment with oleuropein (12 and 18 mg/kg) significantly increased the ulcer index inhibition (percent), in comparison with oleuropein (6 mg/kg). Glutathione peroxidase (GPx) activity was significantly lower in the ethanol group when compared with the other groups whereas, treatment of rats with oleuropein (12 mg/kg) significantly increased glutathione content in gastric tissue when compared with the other groups, and lipid peroxidation was significantly reduced in the oleuropein- (12 and 18 mg/kg) and ranitidine-treated animals. Superoxide dismutase (SOD) and catalase (CAT) activities were both much higher in oleuropein-treated rats than the ethanol group, and although there was a moderate increase in SOD and CAT activities in ranitidine-treated rats, the differences were not significant. These findings suggest that oleuropein has beneficial antioxidant properties against ethanol-induced gastric damages in the rat. Therefore, it seems that a combination regimen including both antioxidant and antisecretory drugs may be beneficial in prevention of ethanol-mediated gastric mucosal damages....(more)
Alirezaei M, et al. J Physiol Biochem 2012 Dec;68(4):583-92.
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